Factors governing the behavior of air contaminants within a few meters of point sources - picometeorology - will be examined. Theoretical and/or empirical equations for prediction of exposures of people within 1 m and from 1 to 10 m of indoor sources will be developed. The methods which minimize exposures to toxic or irritating aerosols and vapors with the lowest energy expenditure will be described. Methods will be applicable to control of sidestream cigarette smoke and various domestic, commercial and industrial indoor air contaminants. Experiments will be conducted in a 3 x 3 x 3 m chamber equipped with separate and controllable inlet and exhaust ventilation. Thermal point sources and organic solvent contamination sources will be simulated, their behavior measured and described under varying ventilation conditions. Typical general ventilation configurations will be modeled. Methods of estimating mixing ("K") factors for widely varied ventilation conditions will be developed and tested. A procedure for calculating potential exposures to health-damaging aerosols and vapors, including cigarette smoke, in public places and industry will be published.